A nichrome vaporized film and a tantalum nitride film ar well-known thin film resistor materials in the microelectronics field, used to make electric resistors. These thin films feature the capability of photolithognaphy. However, the surface of a substrate used to form a resistor must be fine-grained since the thickness of the films, with good high frequency characteristics, is about 200 .ANG.. These films have another drawback, in that the film quality deterioration temperature is as low as about 200.degree. C. The low deterioration temperature means that the burnout temperature is low. Therefore, the working environment for electric resistors, using conventional thin film resistance materials, has been limited considerably.
In regards to the power detector, in Japanese Patent Disclosure No. 84-23263 one of the inventors of this invention has disclosed a thermocouple device made by connecting a mixed crystal film of the amorphous and microcrystal phases with a metal resistance film. A power detector using this thermocouple device is quite capable of stable measurement during high power detection. However, this power detector comprising the thermocouple is too low in sensitivity to perform stable measurement and has poor linearity in the theremo-electromotive force of the thermocouple in detecting low power, such as 1 .mu.W for example. U.S. patent application Nos. 896131 (now U.S. Pat. No. 4,835,059) and 068273., (now U.S. Pat. No. 4,766,008) that one of the inventors of this invention have filed, discloses a Si-Ge alloy thin film conductor in which the amorphous and microcrystal phases coexist. This thin film conductor, though made of a semiconductor material, has a relatively large conductivity but the temperature coefficient is small like that of metals and also offers a feature that the thermoelectric power (the Seebeck coefficient magnitude) is large like that of semiconductors; therefore, the thermo-electromotive force is large. In the above patent applications, the applicability to electric resistors and power detectors is indicated.